The purpose of this study is to determine if 2 doses of Pneumococcal Conjugate Vaccine (PCV) followed by 1 dose of Pneumococcal Polysaccharide Vaccine (PPV) in HIV-infected children on anti-HIV therapy is helpful and safe in fighting pneumococcal infections in this group of children. This study will also look at the protection provided by childhood vaccination against measles, pertussis, and hepatitis B virus.